package com.cspg.design.widget;

import android.content.Context;
import android.graphics.Matrix;
import android.graphics.PointF;
import android.util.AttributeSet;
import android.view.GestureDetector;
import android.view.MotionEvent;
import android.view.View;
import android.widget.ImageView;
import android.util.FloatMath;
/**
 * 图片缩放和拖动类
 * @Title: BaseDragZoomImageView.java
 * @Package com.jonkming.easyui.image.dragzoom.ui
 * @author HuangMingming
 * @date 2016/11/7 17:40
 * @version V1.0
 */
public class BaseDragZoomImageView extends ImageView{

    /** 记录是拖拉照片模式还是放大缩小照片模式 */
    private int mode = 0;// 初始状态
    /** 拖拉照片模式 */
    private static final int MODE_DRAG = 1;
    /** 放大缩小照片模式 */
    private static final int MODE_ZOOM = 2;

    /** 用于记录开始时候的坐标位置 */
    private PointF startPoint = new PointF();
    /** 用于记录拖拉图片移动的坐标位置 */
    private Matrix matrix = new Matrix();
    /** 用于记录图片要进行拖拉时候的坐标位置 */
    private Matrix currentMatrix = new Matrix();

    /** 两个手指的开始距离 */
    private float startDis;
    /** 两个手指的中间点 */
    private PointF midPoint;

    private GestureDetector mGestureDetector;

    public BaseDragZoomImageView(Context context, AttributeSet attrs, int defStyle)
    {
        super(context, attrs, defStyle);
        BaseDragZoomImageView.MatrixTouchListener mListener=new BaseDragZoomImageView.MatrixTouchListener();
        setOnTouchListener(mListener);
        mGestureDetector=new GestureDetector(getContext(), new BaseDragZoomImageView.GestureListener(mListener,this));
    }

    public BaseDragZoomImageView(Context context, AttributeSet attrs)
    {
        this(context, attrs, 0);
        BaseDragZoomImageView.MatrixTouchListener mListener=new BaseDragZoomImageView.MatrixTouchListener();
        setOnTouchListener(mListener);
        mGestureDetector=new GestureDetector(getContext(), new BaseDragZoomImageView.GestureListener(mListener,this));
    }

    public BaseDragZoomImageView(Context context)
    {
        this(context, null);
        BaseDragZoomImageView.MatrixTouchListener mListener=new BaseDragZoomImageView.MatrixTouchListener();
        setOnTouchListener(mListener);
        mGestureDetector=new GestureDetector(getContext(), new BaseDragZoomImageView.GestureListener(mListener,this));
    }

    public void setParentVisibility()
    {
        View v = (View) this.getParent();
        if (v != null)
        {
            if (v.getVisibility() == View.VISIBLE) {
                v.setVisibility(View.GONE);
            } else {
                v.setVisibility(View.VISIBLE);
            }

        }
    }

    /** 计算两个手指间的距离 */
    private float distance(MotionEvent event) {
        float dx = event.getX(1) - event.getX(0);
        float dy = event.getY(1) - event.getY(0);
        /** 使用勾股定理返回两点之间的距离 */
        return (float) Math.sqrt(dx * dx + dy * dy);
    }

    /** 计算两个手指间的中间点 */
    private PointF mid(MotionEvent event) {
        float midX = (event.getX(1) + event.getX(0)) / 2;
        float midY = (event.getY(1) + event.getY(0)) / 2;
        return new PointF(midX, midY);
    }

    public class MatrixTouchListener implements View.OnTouchListener {

        @Override
        public boolean onTouch(View v, MotionEvent event) {
            /** 通过与运算保留最后八位 MotionEvent.ACTION_MASK = 255 */
            switch (event.getAction() & MotionEvent.ACTION_MASK) {
                // 手指压下屏幕
                case MotionEvent.ACTION_DOWN:
                    mode = MODE_DRAG;
                    // 记录ImageView当前的移动位置
                    currentMatrix.set(getImageMatrix());
                    startPoint.set(event.getX(), event.getY());
                    break;
                // 手指在屏幕上移动，改事件会被不断触发
                case MotionEvent.ACTION_MOVE:
                    // 拖拉图片
                    if (mode == MODE_DRAG) {
                        float dx = event.getX() - startPoint.x; // 得到x轴的移动距离
                        float dy = event.getY() - startPoint.y; // 得到x轴的移动距离
                        // 在没有移动之前的位置上进行移动
                        matrix.set(currentMatrix);
                        matrix.postTranslate(dx, dy);
                    }
                    // 放大缩小图片
                    else if (mode == MODE_ZOOM) {
                        float endDis = distance(event);// 结束距离
                        if (endDis > 10f) { // 两个手指并拢在一起的时候像素大于10
                            float scale = endDis / startDis;// 得到缩放倍数
                            matrix.set(currentMatrix);
                            matrix.postScale(scale, scale,midPoint.x,midPoint.y);
                        }
                    }
                    break;
                // 手指离开屏幕
                case MotionEvent.ACTION_UP:
                    // 当触点离开屏幕，但是屏幕上还有触点(手指)
                case MotionEvent.ACTION_POINTER_UP:
                    mode = 0;
                    break;
                // 当屏幕上已经有触点(手指)，再有一个触点压下屏幕
                case MotionEvent.ACTION_POINTER_DOWN:
                    mode = MODE_ZOOM;
                    /** 计算两个手指间的距离 */
                    startDis = distance(event);
                    /** 计算两个手指间的中间点 */
                    if (startDis > 10f) { // 两个手指并拢在一起的时候像素大于10
                        midPoint = mid(event);
                        //记录当前ImageView的缩放倍数
                        currentMatrix.set(getImageMatrix());
                    }
                    break;
            }
            setImageMatrix(matrix);
            return true;
        }

    }

    private class  GestureListener extends GestureDetector.SimpleOnGestureListener {
        private final BaseDragZoomImageView.MatrixTouchListener listener;
        private final BaseDragZoomImageView baseDragZoomImageView;
        public GestureListener(BaseDragZoomImageView.MatrixTouchListener listener,BaseDragZoomImageView view) {
            this.listener=listener;
            this.baseDragZoomImageView = view;
        }
        @Override
        public boolean onDown(MotionEvent e) {
            //捕获Down事件
            return super.onDown(e);
        }
        @Override
        public boolean onDoubleTap(MotionEvent e) {
            //触发双击事件
            baseDragZoomImageView.setParentVisibility();
            return super.onDoubleTap(e);
        }
        @Override
        public boolean onSingleTapUp(MotionEvent e) {
            // TODO Auto-generated method stub
            return super.onSingleTapUp(e);
        }

        @Override
        public void onLongPress(MotionEvent e) {
            // TODO Auto-generated method stub
            super.onLongPress(e);
        }

        @Override
        public boolean onScroll(MotionEvent e1, MotionEvent e2,
                                float distanceX, float distanceY) {
            return super.onScroll(e1, e2, distanceX, distanceY);
        }

        @Override
        public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,
                               float velocityY) {
            // TODO Auto-generated method stub

            return super.onFling(e1, e2, velocityX, velocityY);
        }

        @Override
        public void onShowPress(MotionEvent e) {
            // TODO Auto-generated method stub
            super.onShowPress(e);
        }

        @Override
        public boolean onDoubleTapEvent(MotionEvent e) {
            // TODO Auto-generated method stub
            return super.onDoubleTapEvent(e);
        }

        @Override
        public boolean onSingleTapConfirmed(MotionEvent e) {
            // TODO Auto-generated method stub
            return super.onSingleTapConfirmed(e);
        }

    }
}